Electrical fitting



Feb. 21, 1928. 1,659,648

H. A. DOUGLAS ELECTRICAL FITTING Filed Jan. 27. 1.926

Patented Feb. 21, 1928.

UNITED STATES HARRY A. DOUGLAS, OF BRONSON, MICHIGAN.

ELECTRICAL IITTIN G.

Application filed January 27, 1926. Serial No. 84,096.-

My invention resides in a new article of manufacture which is in the form of a shell having a cylindrical body portion and a flange projecting laterally beyond the shell and located at one end thereof, the body portion of the shell having an annular outwardly bulging fold. U-shaped in cross section, formed therein and slightly spaced apart from said flange, and a bayonet slot formed in said shell and continued at one end into and through the inner ed e portion of the flange in alignment with the shell body.

The device of my invention is of particular service for separably holding an incandescent lamp within a concave reflector, the bottom of the reflector having a circular hole formed therethrough and conforming in d1- ameter to the exterior of the body portion of the shell, which body portion is snugly received in this hole, the portion of the reflector margining said hole being clamped between the aforesaid flange and said fold or head by crowding the flange against the reflector which is consequently held tight against the bead. By this construction, the notching of the reflector to receive the bayonet pin is not required as the bayonet slot is entirely within the circular hole in the reflector and is continued clear to'the exterior of the flange so as readily to admit the bayonet pin.

The invention will be more fully explained in connection with the accompanying drawing in which Fig. 1 illustrates the device of my invention in elevation together with a lamp and terminal plug supported thereby and a support therefor; Fig. 2 is a longitudinal sectional view of the structure shown in Fig. 1; Fig. 3 is a front View; Fig. 4 is a perspective view of parts of the structure shown in 'Fig. 1 with the lamp omitted; and Fig. 5 is a view, somewhat diagrammatic, illustrating part of the process of forming the new device.

In the drawing, the shell of my invention has a cylindrical body portion 1 formed with a flange 2 projecting laterally beyond the shell and located at the front end thereof, the body portion of the shell having an annular bead 3 bulging outwardly from the shell and U-shaped in cross section. The bead and flange are slightly spaced apart to receive the bottom end of a reflector 4 or other support that is interposed between the flange and head, the circular hole in the reflector being of a size to produce a snug lit between the body of the shell and the reflector to avoid transverse relativemovement between these two parts. I have shown two bayonet slots each having a longitudinal branch 5 and an inner and transverse branch 6. These slots are formed through the opposite sides of the shell and are evenly continued along the shell and through the flange so that there is no obstruction in the slots to the passage of bayonet pins, such as the pins 7 provided upon the base 8 of the incandescent lamp 9. The outer end of each bayonet slot being thus continued into the flange, extends slightly across the flan e to terminate in line with the outer cylinf surface of the shell body and the edge-of the circular hole in the support 4. The flange is thus circularly continuous beyond its junction with the shell body and serves firmly to hold the shell body in assembly with the shell support 4 at all places throughout the circle of the flange, the flange being compressed against said support and tightly compressing the support against the head 3.

In the process of forming the device of my invention, the shell is initially unflanged and the slots are formed therein and terminate short of the front end of the shell a distance corresponding to the intended Width of the flange less the thickness of the shell as illustrated in Fig. 5. When the flange is formed, it is reduced in width by and at the slots to the extent of the thickness of the shell so that the slots'are freely open at their front ends for the reception of the corresponding bayonet pins. Thereafter, the head is formed y compressing the shell body lengthwise. The drawing shows the use of the device of my invention in connection with a single pole lamp whose base 8 is furnished with a metallic sheath in electrical connection with one terminal of the lamp filament and with the metallic bayonet pins. The bayonet pins are in electrical connection with the metallic shell 1 which is suitably grounded. The other terminal of the lamp filament is electrically connected with the contact 10 that is carried at the center of the rear face of the lamp base to be engaged by a forwardl spring-pressed contact 11' projecting througl i the front end of a spring barrel 12 which is carried within an insulating plug 13 that secured to and within the rear end of the shell. The spring barrel 12 is formed to rical and located at one end thereof, the body portion of the shell having an annular ont- Wardly bulging told, U shaped in cross section, formed therein and slightly spaced apart from said flange, and a bayonet slot formed in said shell and continued at one end into and through the inner edge portion of the flange in alignment with the shell body.

In witness whereof, I hereunto subscribe my name.

HARRY A. DOUGLAS. 

